Study On The Relationship Between Health-Related Physical Fitness And Mental Behavior Problems And Exercise Intervention Of Adolescents

Adolescence is a stage of high prevalence of a variety of mental and behavior problems.Depression,anxiety and non-suicidal self-injury（NSSI）are the most common and serious mental and behavior problems in the adolescents.Mental sub-health is a process mental behavior problem which is easy to appear in the unstable period of adolescent mental development.All the above are the prominent problems affecting the development of adolescent mental health.Previous studies have shown that the mental behavior problem of Chinese adolescents is not optimistic.In recent years,the development of society has lead to the adolescents who are in the period of psychological changeability to bear more competitive pressure and face more severe psychological difficulties and fluctuations than before.Adolescence is not only a sensitive stage of psychological development,but also a period of forming various behavioral habits.This period of psychological development has plasticity.Avoiding risk factors and increasing protective factors can promote mental health development of adolescents.Some studies suggest that health-related physical fitness（HPF）can play an important role in preventing mental behavioral problems.HPF is closely related to physical health and is an independent predictor of the risk of many diseases.Compared with other factors,the intervention for HPF has the advantages of controllability,efficiency and universality.Paying special attention to the relationship between HPF and mental behavior problems of adolescents,so as to promote the improvement of mental behavior problems from the perspective of improving adolescents’HPF.It will not only add substantive evidence to confirm the mutual influence between physical and mental,but also provide concrete and practical guidance for improving adolescents’mental health.It has important theoretical and practical significance for improving the health of adolescents under the new situation.In view of this,a total of 10,327 adolescents aged 12-17 years（5,231 boys and 5,096girls）from Shanghai,Urumqi,Suzhou,Kunming and Changsha were selected by stratified cluster random sampling method to conduct a physical fitness test and a survey of mental behavior problems.The aim of this study is to explore the relationship of adolescents’HPF each items and mental behavior problems.On this basis,to explore the improvement effect of exercise on mental behavior problems after the intervention of adolescent HPF.Specifically,it includes the following three studies:Ⅰ Study on Influencing Factors of adolescent mental behavior problemsObjcetive:To analyze the factors affecting mental behavior problems of adolescents.Methods:Stratified cluster random sampling method was used to select about180 boys and about 180 girls from each age groups of 12-17 years in Shanghai,Kunming,Urumqi,Suzhou and Changsha.Totaling 10,327 adolescents.Mental behavior problems were investigated by using the‘Center for Epidemiological Survey,Depression Scale’,‘Self-Rating Anxiety Scale’and other questionnaires.HPF were tested for height,weight,20m Shutter run test（20m SRT）,Standing long jump,30s sit-ups,sit-and-reach test,and the basic information were investigated by questionnaire survey.Data were analyzed by Chi-square test,logistic regression and other methods.Results:（1）The status of Mental behavior problems:The prevalence of mental sub-health status,depression symptom（including severe depression）,anxiety and NSSI in adolescents were 22.4%,28.6%（severe depression accounted for 9.1%）,15.1%and 25.1%,respectively.25.1%of the adolescents had two or more mental behavior problems.（2）Influencing factors of mental behavior problems:The risk of mental behavior problems in adolescents with lowest,lower and higher grades of the health-related physical fitness composite z-score（HPF-Z）is higher than that of adolescents with high grade of HPF-Z（OR=1.433,1.239,1.127,P<0.05）.Age could positively predict the risk of mental behavior problems（OR=1.068,P<0.001）.female adolescents have higher risk of multiple mental behavior problems（OR=1.449,P<0.001）.Compared with Urumqi,adolescents in Shanghai,Changsha,Kunming and Suzhou had higher risk of mental behavior problems（OR=1.460～1.600,P<0.001）.The non-only child,adolescents of low SES group,single-parent families and step families had higher risk of mental behavior problems（OR=1.093～1.759,P<0.05）.Adolescents with insufficient sleep duration on school days and weekends,sufficient sleep duration on school days or weekends,and screen time≥2h per day had higher risk of mental behavior problems（OR=1.603～2.053,P<0.001）.Summary:（1）The current situation of mental sub-health status（22.4%）,depressive symptoms（28.6%,Severe depression accounted for 9.1%）and NSSI were serious.Up to a quarter of the adolescents had two or more mental behavior problems.（2）Adolescents with a good family environment and a health lifestyle have better mental health.Higher level of HPF can reduce the risk of mental behavior problems in adolescents.Ⅱ The relationship between health-related physical fitness and mental behavior problems in adolescentsObjcetive:On the basis of study 1 finding that adolescents with lower HPF are at higher risk for metal behavior problems.To analyze the relationship between adolescent HPF items and mental behavior problems,so as to provide evidence for formulating more targeted intervention measures.Methods:The samples are the same as those in the research1.Data were analyzed by Univariate analysis of variance,Spearman correlation,Kruskal-Wallis H test,Chi-square test and logistic regression.Results:（1）Body composition:The score of mental sub-health of normal weight girls(P₅₀=55)was higher than that of obese girls（60）.The scores of depression and anxiety in normal weight girls（11）were lower than overweight（12）and obese girls（12）.The total number of NSSI in obese boys[0（0,1）]was higher than normal weight boys.The differences were statistically significant（P<0.05）.After controlling for confounding factors,there was a statistically significant upward trend in the prevalence of mental behavior problems among adolescents with increased BMI grade（P-trend<0.001）.（2）Muscle fitness:The scores of mental sub-health（58）,depression（12）,anxiety（41）and NSSI[0（0,1.3）]in the lowest grade of Girls standing long jump ware all higher than those in the highest grade group（P<0.05）.The score of mental sub-health of boys with lowest grade of 30s sit-up was the highest（52）.The differences were all statistically significant（P<0.05）.After controlling for confounding factors,the prevalence of all mental behavior problems among adolescents decreased with the standing long jump grade increased（P-trend<0.01）.The prevalence of mental behavior problems among adolescents decreased with the 30s sit-up grade increased（P-trend<0.001）.（3）Cardiorespiratory fitness:The scores of depression and anxiety in lowest grade boys of 20m SRT（11,40）were higher than those of highest grade group（10,38）.The lowest grade girls had the highest depression and anxiety scores（12,42）.The differences were all statistically significant（P<0.05）.After controlling for confounding factors,the prevalence of all mental behavior problems among adolescents decreased as the 20m SRT grade increased（P-trend<0.01）.（4）Flexibility:The anxiety score of the highest grade group（38）was lower than that of the lowest grade group（40）and the higher grade group（40）.The anxiety scores of girls in highest and higher grade groups（41）were higher than those in lower and lowest grade groups（40）.The differences were all statistically significant（P<0.05）.After controlling for confounding factors,the prevalence of mental behavior problems in adolescents decreased with the increase of the grade of sit-and-reach（P-trend<0.05）.（5）HPF-Z:After controlling for confounding factors,the prevalence of all mental behavior problems in adolescents decreased with the increase of HPF-Z grade（P-trend<0.01）.Summary:（1）Adolescents with better HPF had better mental health.（2）After controlling for confounding factors,the incidence of mental behavior problems in adolescents showed a downward trend with the increase of HPF.（3）Among the items of HPF,muscular strength and CRF are more closely related to adolescent mental behavior problems.Ⅲ Exercise intervention for adolescent health-related physical fitness and mental behavior problemsObjcetive:To explore the influence of HPF improvement on adolescent mental behavior problems through exercise intervention.Methods:In the sample of study one,407 students in middle and high school in Suzhou were randomly selected to participate in exercise intervention.The intervention group received exercise intervention 3 times a week for 10 weeks,while the control group received normal school daily physical education courses without additional intervention.Before and after the intervention,HPF test and questionnaire survey were conducted.Data were analyzed by t test,chi-square test,Mann-Whitney U test,Wilcoxon test and Mediation effect analysis.Results:（1）In addition to the BMI of middle school girls and high school boys,the absolute values of difference in all items of HPF and HPF-Z in the intervention group were greater than those in the control group（t ranged from-4.915 to 11.666,P<0.05）.（2）After intervention,the prevalence of mental sub-health,depressive symptoms,NSSI（girls）and the total mental behavior problems in the intervention group were lower than before intervention（P<0.05）,and the prevalence of mental sub-health,depressive symptoms,anxiety symptoms（girls）and the total mental behavior problems（girls）in the intervention group were lower than those in the control group（P<0.05）.After intervention,the results of each mental behavior problem in the intervention group were lower than those before intervention（Z ranged from-6.157 to-2.655,P<0.05）.The absolute values of differences of mental sub-health,depression,anxiety scores,and the total number of NSSI in the intervention group were higher than those in the control group（Z ranged from-6.712 to-2.212,P<0.05）.（3）HPF played a partial mediating role in the intervention of exercise on adolescent mental sub-health,depression and anxiety in adolescents（mental sub-health:B=-3.492,P<0.001;Depression:B=-1.054,P<0.001;Anxiety:B=-1.007,P<0.01）.The mediating effect contribution rates were 39.2%,44.1%and 35.8%,respectively.HPF did not play a mediating role in the exercise intervention on NSSI in adolescents.Summary:（1）HPF and mental health of adolescents were improved by exercise intervention.（2）The effect of exercise intervention on adolescents’mental sub-health,depression and anxiety was partly mediated by the HPF,which had no mediating effect in NSSI.Conclusion:（1）The current situation of mental sub-health status,depressive symptoms and NSSI were serious.Up to a quarter of the adolescents had two or more mental behavior problems.Adolescents who have a favorable family environment,maintain a healthy lifestyle,and possess higher levels of HPF exhibit superior mental health.（2）There was a dose-effect relationship between HPF items and multiple mental behavior problems.With the increase of HPF,the mental health of adolescents is on the rise.Among them,muscle strength,CRF are more closely related with mental behavior problems.（3）Exercise intervention can improve adolescent HPF and mental health.HPF plays a partial mediating role in the intervention of exercise on mental sub-health,depression and anxiety in adolescents.